1. Field
Embodiments of the invention relate to electronic systems, and in particular, to serial and parallel interfaces for electronic systems.
2. Description of the Related Technology
Various electronic systems, such as mixed-signal electronic systems, can include an interface for writing data to and/or reading data from one or more integrated circuits (ICs). The interface can include either a serial interface or a parallel interface. For example, a radio frequency system can include a serial peripheral interface (SPI) bus for writing and reading registers of an RF switch or digital attenuator. As an alternative example, a radio frequency system can implement a parallel general purpose I/O (GPIO) interface. Another alternative interface is the Mobile Industry Processor Interface (MIPI/SPI). The registers can include information for setting, for example, a power mode and/or a frequency band of operation of a power amplifier.
A radio frequency system with a serial interface can include specialized interface circuitry. Therefore, a radio frequency system implementing a serial interface typically has a different physical hardware design from a radio frequency system implementing a parallel interface. Accordingly, if a system designer wishes to provide customers a choice of interface, it may produce multiple product versions, each implementing different interfaces. There are significant costs associated with this approach, such as the need for additional semiconductor processing masks, inventory management, additional development costs, schedule delays, etc. Once the designer decides which interface to provide, the hardware is designed with either one of the above interfaces. Typically, the interfaces cannot be interchanged, because each interface has different inputs and protocols. Often, the interface requirement is changed after the design is complete. Sometimes, different customers require different interfaces.
Alternatively, the system designer could implement both serial and parallel interfaces in the same product. This approach typically requires additional pins and duplication of interface circuitry, further complicating manufacture and packaging. Accordingly, a conventional implementation of dual interfaces also carries significant costs.
There is a need products with the flexibility to be used in diverse interface environments. Furthermore, there is a need for a flexible interface that has reduced development costs through a single multipurpose design, and which requires fewer pins.